The azimuthal asymmetry in the lepton pair from linearly polarized
photons in UPC has been studied in the TMD factorization formalism
[1]}, [2]} similar to polarized gluons [3]}, [4]}, [5]}.
In this formalism, the photon Wigner functions are introduced into
the cross section which depend on the transverse momentum and coordinate
[6]}, [7]}. The broadening of transverse
momentum has also been studied in the TMD formalism [8]}.
